The presidency of Ronald Reagan began on January 20, 1981, when Ronald Reagan was inaugurated as President of the United States, and ended on January 20, 1989. Reagan, a Republican, took office as the 40th United States president following a landslide win over Democratic incumbent President Jimmy Carter in the 1980 presidential election. Reagan was succeeded by his vice president, George H. W. Bush, who won the 1988 presidential election with Reagan's support.
Domestically, Reagan introduced several tax cuts and sought to cut non-military spending. The economic policies enacted in 1981, known as "Reaganomics", were inspired by supply-side economics. The Tax Reform Act of 1986 simplified the tax code, reducing rates while removing several tax breaks. Reagan also appointed more federal judges than any other president, including four Supreme Court Justices. Reagan signed the Immigration Reform and Control Act of 1986, which enacted sweeping changes U.S. immigration law, and the administration escalated the "War on Drugs".
Reagan's foreign policy stance was resolutely anti-communist; its plan of action, known as the Reagan Doctrine, sought to roll back the global influence of the Soviet Union in an attempt to end the Cold War. Under this doctrine, the administration initiated a massive buildup of the military, promoted new technologies such as missile defense systems, and, in 1983, undertook an invasion of Grenada, the first major overseas action by U.S. troops since the end of the Vietnam War. It also controversially granted aid to paramilitary forces seeking to overthrow leftist governments, particularly in war-torn Central America and Afghanistan. During Reagan's second term, he sought closer relations with Soviet leader Mikhail Gorbachev, and the two leaders signed the INF Treaty, a major arms control agreement. The Reagan administration engaged in covert arms sales to Iran in order to fund the Contra rebels in Nicaragua that were fighting to overthrow their socialist government. The resulting Iran–Contra affair resulted in the conviction or resignation of several administration officials.